Cutting oil containing defoamant



United States Patent 3,287,268 CUTTING OIL CONTAINING DEFOAMANTFrederick E. Tice, Bayonne, N.J., assignor to Esso Research andEngineering Company, a corporation of Delaware No Drawing. Filed Nov.21, 1963, Ser. No. 325,483 4 Claims. (Cl. 252-48.4)

The present invention relates to improvements in sulfurized orchlorinated cutting oils and is particularly concerned with themodification of such oils to reduce their foam-forming tendencies.

Cutting oils serve to remove the heat generated during machining ofmetal and to lubricate the cutting tool against the work and chips. Thetypes of cutting oils employed vary greatly, depending upon the cuttingconditions and the metals being cut. For most commonly encounteredcutting operations employing various steels and cast iron, the so-calledtransparent cutting oils which contain sulfur and/or chlorine compoundsare widely used and do an excellent job.

Because of the need for a large quantity of cutting oil during thecutting operation, the oil is often sprayed at high pressure into thecutting zone. In addition, in many operations, the chips and turningswhich accumulate at the machine are collected and centrifuged to recoverthe cutting oil which is then returned to the machine. These two factorsviz., spraying and centrifuging, as well as other factors associatedwith a circulating cutting oil system promote the formation of foam. Inorder to prevent this objectional foam-forming tendency of the cuttingoil, a defoaming agent may be employed. In some environments, well-knownsilicone defoamants are employed. However, in certain instances the useof silicone is prohibited. An example of such an instance is in thoseoperations where the metal being machined is subsequently painted. Here,the presence of silicone, even in minute quantities, cannot betolerated.

By means of the present invention there is provided anonsilicone-containing defoamant for sulfurized and/or chlorinatedcutting oil. In addition, there are provided an improved cutting oilcomposition which exhibits antifoamant properties and a method forreducing the foaming encoutered in circulating cutting oils systems.

According to the present invention, it has been surprisingly found thatthe use of about 0.05 to 0.5 volume percent of an alkenyl succinic acidester derivative in a cutting oil, hereinafter defined, effectivelyreduces the tendency of the oil to produce foam and lessens thestability of the foam that is produced.

The alkenyl succinic acid ester derivative employed in the presentinvention comprises a mixture of an alkenyl succinic acid and an esterformed from that acid, or from a related alkenyl succinic acidcontaining about 8 to 30 carbon atoms in the alkenyl group, and a glycolof 2 to 4 carbon atoms.

The mixture of acid and ester may be prepared by reacting an alkenylsuccinic anhydride with about an equimolar quantity of a glycol at atemperature of about 75 to 400 F., for about 1 to 24 hours, followed bythe addition of an additional quantity of the same or a related alkenylsuccinicanhydride and about an equimolar quantity of Water. Thispreparation may, if desired, be carried out in a mineral oil diluent.

The preparation of alkenyl succinic anhydrides is well known in the artand simply involves the reaction of maleic anhydride with an olefiniccompound, usually in equimolar proportions, though in some casessomewhatof an excess of olefinic material is used. Generally, the reactioninvolves simple heating, but in other cases catalytic means may beemployed. Since relatively pure olefins ice are difficult to obtain orare often too expensive for commercial use, alkenyl succinic acidanhydrides are ordinarily prepared as mixtures by reacting mixed olefinswith maleic anhydride. Such mixtures, as well as relatively pure alkenylsuccinic anhydrides, may be employed in this invention. Mixed alkenylsuccinic anhydrides wherein the alkenyl group averages 6 to 8, 8 to 10,and 10 to 12 carbon atoms, are commercially available.

Alkenyl succinic anhydrides can also be prepared by reaction of lowmolecular weight polymers of C to C olefins with maleic anhydride. Thus,a C or a C alkenyl succinic anhydride can be prepared in this mannerfrom tetrapropylene or from tetraisobutylene, respectively.

While the preferred derivative is the hereinafter described mineral oilconcentrate containing a mixture of tetrapropenyl succinic acid and themonoester of said acid with propylene glycol, other alkenyl succinicacid derivatives as Well as other methods of preparation may be used.(By tetrapropenyl is meant the C alkyl group derived fromtetrapropylene.) For example, the ester may be prepared by using C to Cglycols, such as ethylene glycol, or butylene glycol; the acid may beany alkenyl succinic acid wherein the alkenyl group contains from about8 to 30 carbon atoms, for example, 0,, from diisobutylene, C fromtripropylene, C from pentapropylene, C to C from polyisobutylene ofabout 300 molecular weight, etc.; the relative proportions of said acidand said ester may vary widely but will usually range from about 40 tovolume percent acid and 20 to 60 volume percent ester. In addition, thederivative may be prepared with or without the use of a petroleumdiluent. Thus, the amount of diluent may also vary widely, for example,from about 0 to 80 weight percent, preferably from about 30 to 50 weightpercent.

The derivative may be prepared from two different alkenyl succinicacids, for example, the free acid may be diisobutylene succinic acid andthe monoester may be prepared from butylene glycol and tripropylenesuccinic acid. An ester containing terminal hydroxy groups may beprepared by reacting about equimolar quantities of the alkenyl succinicacid with an alkylene oxide of from 2 to 4 carbon atoms, for example,ethylene oxide, propylene oxide or butylene oxide.

The alkenyl succinic acid ester derivative preferred for use comprises60 weight percent of a mixture of 60 volume percent tetrapropenylsuccinic acid, 40 volume percent monoester of tetrapropenyl succinicacid with 1,2- propane diol, and 40 weight percent of a petroleumdiluent. This derivative may be prepared by reacting about 0.4 mole oftetrapropenyl succinic anhydride in mineral oil with 0.4 mole ofpropylene glycol at a temperature of about 75 to 400 F., preferably 180to 250 F. for about 1 to 24 hours, preferably 3 to 5 hours, followed bythe addition of 0.6 mole of tetrapropenyl succinic anhydride and 0.6mole of water and hydrolysis at' about 75 to 300 F., preferably to 200F.

The cutting oils to which the succinic acid derivative may be added inaccordance with the present invention are the so-called transparentcutting oils and the black oils. Both oils are characterized by thepresence of sulfur and/or chlorine-containing materials which impartextreme pressure properties to the oils. The black oils differ from thetransparent oils in that the former contain larger amounts of sulfurand/or chlorine-containing These oils are well known in materials thanthe latter. the art and the following description of such oils is notintended to limit the present invention in any respect. Such oilsinclude: sulfurized hydrocarbon oils and hydrocarbon oils to whichvarious sulfurized and/or chlorinated materials have been added, such assulfurized fattyoils, sulfurized solvent extracts of mineral oils,sulfurized esters, sulfurized olefin polymers, chlorinated waxes,chlorinated aromatics, chlorinated esters, and the like.

sulfurization is usually accomplished with free sulfur or with sulfurmonochloride or with a combination of these agents. The sulfurization ofa mineral hydrocarbon oil may be effected, for example, by addingelemental sulfur thereto and heating to 250 to 300 F. or higher. In someinstances it is merely necessary to add the sulfur to the mineral oil ata temperature high enough to melt the sulfur, stir the sulfur into theoil, and then cool the mixture.

An animal or vegetable oil such as sperm oil, lard oil, cottonseed oil,peanut oil, or the like, may similarly be sulfurized by adding sulfurthereto, as for example, 6 to 12% sulfur, and heating at a temperaturein the range of say 300 to 375 F. for 1 to 3 hours. The sulfurization ofthe fatty oil may be accomplished in the presence of the fatty oilalone, in which case the sulfurized product is subsequently blended witha mineral lubricating oil, or alternatively, the fatty oil may besulfurized in the pres ence of the mineral lubricating oil.

Among the sulfurized materials that may be employed in preparing cuttingoils in accordance with the present invention are included: thesulfurized esters of abietic acid described in U.S. Patent 2,217,764,the sulfurized solvent extracts of petroleum fractions described in U.S.Patents 2,222,643 and 2,227,952, the sulfurized olefin polymersdescribed in U.S. Patent 2,246,282, and the sulfurized oils prepared inaccordance with U.S. Patents 2,246,282 and 2,467,137. It is to beunderstood, of course, that the invention is not limited to theseparticular types of materials.

Chlorination is usually accomplished with elemental chlorine gas. Thechlorination of a mineral hydrocarbon may be effected, for example, bycontacting the hydrocarbon at 175 to 200 F. with chlorine gas, with orwithout the aid of a catalyst as desired. The product is subsequentlystripped of excess chlorine and hydrogen chloride reaction product andcooled.

Among the chlorinated materials that may be employed in preparing thecutting oils in accordance with the present invention are included:chlorendic acid esters; the sulfurized esters of chlorendic aciddescribed in U.S. Patent 2,969,326; chlorinated aromatics, for example,chlorinated biphenyl; chlorinated wax; chlorinated naphthalenes; and thelike.

In general, the cutting oils will contain about 0.1 to 5.0 weightpercent sulfur and/ or about 0.05 to 5.0 weight percent chlorine,preferably about 0.4 to 0.8 weight percent sulfur and 0.05 to 0.15weight percent chlorine.

Although a Wide range of lubricating oils may be employed as base stocksfor these cutting oils, in general the base oil will comprise an oilhaving a viscosity at 100 F. in the range of from about 90 to 500Saybolt seconds, an API gravity of from about 23 to about 33, and afiash point above about 300 F. Preferably, a light coastal petroleum oilor naphthenic petroleum oil having a viscosity at 100 F. from about 100to about 300 SUS is used.

The following examples serve to illustrate the manner in which theinvention may be practiced.

Example 1 0.4 mole of tetrapropenyl succinic anhydride and 0.4 mole ofpropylene glycol are reacted in a mineral oil diluent at a temperatureof about 210 to 215 F. for about 4 hours. 0.6 mole of tetrapropenylsuccinic anhydride and 0.6 mole of water are then added to the mixtureand the anhydride is hydrolyzed at about 180 F. The resulting mixtureconsists of 60 weight percent of the reaction product and 40 weightpercent mineral oil diluent.

Example 2 In order to demonstrate the defoamant properties of theadditive of Example 1, two cutting oils were prepared and tested.Cutting oil A was a commercially available sulfur andchlorine-containing oil. This oil (A) consisted of:

Weight percent Base oil 1 98.1 Anglamol 31 2 1.0 Sulchlor 1717-M 0.9

1 Mineral lubricating oil derived from naphthenic distillate having aviscosity of 150 SSU at F.

Lubrizol Corp. additive which contains as active ingredients 42-46% Sand a maximum of 0.2 wt. percent Cl.

Carlyle Chemical Works, Inc. additive which contains as activeingredients a minimum of 9.0 wt. percent S and a minimum of 9.0 wt.percent CI.

Cutting oil B consisted of cutting oil A to which had been added 0.3volume percent of the additive of Example 1,

Cutting oils A and B were tested for foaming characteristics using theASTM-D892 Foam Test and for interfacial tension using the ASTM-D97 l-50Interfacial Tension Test. The results are shown in Table I.

These results show that cutting oil B, containing a defoamant of thepresent invention, has a reduced tendency to produce foam and furtherthe small amount of foam that is produced is unstable.

Example 3 0.2 mole of diisobutenyl succinic anhydride and 0.2 mole ofethylene glycol are reacted at a temperature of 220 F., for about 5hours. 0.8 mole of diisobutenyl succinic anhydride and 0.8 mole of waterare then added to the mixture and hydrolyzed at about 220 F. for about 2hours.

Example 4 A sulfurized cutting oil was prepared by dissolving at about250 F., with stirring, about 1 weight percent of elemental sulfur in anaphthenic oil having a viscosity of about SUS at 100 F. and thenblending 92.5% of the sulfurized aphthenic oil with 7.5% of mixed fattyoils that had been treated with sulfur monochloride to a content ofabout 8% sulfur and 8% chlorine. To this cutting oil, 0.15 volumepercent of the product prepared in Example III can be added.

It is recognized that many modifications of the instant disclosure maybe made without departing from the spirit of the invention as defined bythe appended claims. Further, it is not intended that the examples shownlimit the invention in any respect.

What is claimed is:

1. An improved cutting oil having a reduced tendency to form foam whichcomprises a major proportion of a. lubricating oil having a viscosity at100F. within the range between about 90 to 500 SUS, about 0.05 to 10weight percent of an oil-soluble compound selected from the groupconsisting of sulfurized compounds and chlorinated compounds, and about0.05 to 0.5 volume percent of a mixture of (a) an alkenyl succinic acidand (b) the monoester of an alkenyl succinic acid and a glycolcontaining 2 to 4 carbon atoms; wherein said alkenyl groups in said acidand in said ester each contain about 8 to 30 carbon atoms.

2. An oil according to claim 1 wherein said mixture comprises about 60volume percent of tetrapropenyl succinic acid and about 40 volumepercent of the monoester of tetrapropenyl succinic acid with propyleneglycol.

3. An improved cutting oil having a reduced tendency acid, wherein thealkenyl group contains from about 8 10 to 30 carbon atoms, and (b) 20 to60 volume percent of the monoester of a glycol which contains from 2, to4 carbon atoms and an alkenyl succinic acid wherein the alkenyl groupcontains from about 8 to 30 carbon atoms.

groups of (a) and (b) are both C groups derived from tetrapropylene andsaid glycol is propylene glycol.

References Cited by the Examiner UNITED STATES PATENTS 2,208,161 7/ 1940Prutton ct al 25248.8 2,318,629 5/ 1943 Prutton 252-48.8 2,394,909 2/1946 Gleason 260-48 .5 2,748,086 5/ 1956 Monson 252-358 3,004,92310/1961 Jurisch 252358 FOREIGN PATENTS 896,376 5/ 1962 Great Britain.

DANIEL E. WYMAN, Primary Examiner,

4. An oil as defined by claim 3 wherein the alkenyl 15 L. G. XIARHOS,Assistant Examiner.

1. AN IMPROVED CUTTING OIL HAVING A REDUCED TENDENCY TO FORM FOAM WHICHCOMPRISES A MAJOR PROPORTION OF A LUBRICATING OIL HAVING A VISOCITY AT100*F. WITHIN THE RANGE BETWEEN ABOUT 90 TO 500 SUS, ABOUT 0.05 TO 10WEIGHT PERCENT OF AN OIL-SOLUBLE COMPOUND SELECTED FROM THE GROUPCONSISTING OF SULFURIZED COMPOUNDS AND CHLORINATED COMPOUNDS, AND ABOUT0.05 TO 0.5 VOLUME PERCENT OF A MIXTURE OF (A) AN ALKENYL SUCCINIC ACIDAND (B) THE MONOESTER OF AN ALKENYL SUCCINIC ACID AND A GLYCOLCONTAINING 2 TO 4 CARBON ATOMS; WHEREIN SAID ALKENYL GROUPS IN SAID ACIDAND IN SAID ESTER EACH CONTAIN ABOUT 8 TO 30 CARBON ATOMS.